Illuminated vehicle panel and method for manufacturing an illuminated vehicle panel

ABSTRACT

A method for manufacturing a panel includes forming a path segment on a surface of a substrate from a photoluminescent material. The method further includes overlaying the path segment with an overlay material. The overlay material is configured to render the path segment substantially invisible under an ambient photopic condition and render the path segment visible under an ambient mesopic or scotopic condition.

FIELD

This application generally relates to interior decorations of vehicles.In particular, this application describes an illuminated vehicle paneland a method for manufacturing an illuminated vehicle panel.

BACKGROUND

Airline operators may go to various lengths to improve brand recognitionand customer experience. For example, in an effort to improve brandrecognition, an operator may order aircraft from a manufacturer andspecify in the order that the exterior of all aircraft ordered depict alogo or that all aircraft be painted a particular color. Specifyinglogos and colors may be especially true where the logo and/or colorshave come to be associated with the operator.

In an effort to improve customer experience, the operator may specifythat the interior of the aircraft be decorated in a pleasing mannerand/or that the interior of the aircraft includes certain amenitiesdesired by the operator's passengers. For example, the operator mayspecify the arrangement of the seats, the fabrics used throughout thecabin, and various colors and designs to depict within the aircraft.

SUMMARY

An example of a method for manufacturing a panel includes forming a pathsegment on a surface of a substrate from a photoluminescent material.The method further includes overlaying the path segment with an overlaymaterial. The overlay material is configured to render the path segmentsubstantially invisible under an ambient photopic condition and renderthe path segment visible under an ambient mesopic or scotopic condition.

An example of a panel for an interior cabin of an aircraft includes asubstrate. A path segment is arranged on a surface of the substrate. Thepath segment is formed from a photoluminescent material. An overlaymaterial is arranged on the path segment. The overlay material isconfigured to render the path segment substantially invisible under anambient photopic condition and render the path segment visible under anambient mesopic or scotopic condition.

An example of an aircraft includes a plurality of panels configured forattachment to an interior of a fuselage. At least one panel of theplurality of panels includes a substrate, a path segment, and an overlaymaterial. The path segment is arranged on the surface of the substrate.The overlay material is arranged on the path segment. The overlaymaterial is configured to render the path segment substantiallyinvisible under an ambient photopic condition and render the pathsegment visible under an ambient mesopic or scotopic condition.

BRIEF DESCRIPTION OF THE FIGURES

The accompanying drawings are included to provide a furtherunderstanding of the claims, are incorporated in, and constitute a partof this specification. The detailed description and illustrated examplesdescribed serve to explain the principles defined by the claims.

FIG. 1A illustrates an aircraft, in accordance with an example.

FIG. 1B illustrates an interior section of the aircraft, in accordancewith an example.

FIG. 2A illustrates a top view of a panel for an interior cabin of theaircraft, in accordance with an example.

FIG. 2B illustrates a side view of the panel, in accordance with anexample.

FIG. 2C illustrates a side view of a panel that includes a film layer,in accordance with an example.

FIG. 3A illustrates a panel with an illumination device arranged in anopening of the panel, in accordance with an example.

FIG. 3B illustrates a panel that utilizes a fiber optic cable tooptically communicate light emanating from an illumination device to anopening, in accordance with an example.

FIG. 3C illustrates a panel that utilizes a light pipe to opticallycommunicate light emanating from an illumination device to an opening,in accordance with an example.

FIG. 4 illustrates a view of panel depicting the shape of aconstellation, in accordance with an example.

FIG. 5 illustrates a method for manufacturing the panel of FIG. 1B, inaccordance with an example.

FIG. 6A illustrates a path segment formed on a surface of a substratefrom a photoluminescent material, in accordance with an example.

FIG. 6B illustrates an overlay material overlaying the path segment, inaccordance with an example.

FIG. 6C illustrates openings formed in the substrate, in accordance withan example.

FIG. 7 illustrates a method for manufacturing a panel, in accordancewith an example.

FIG. 8 illustrates a method for illuminating an interior of a cabin ofan aircraft, in accordance with an example.

FIG. 9A illustrates a perspective view of panel having illuminated pathsegments arranged to depict the constellation Ursa Major, in accordancewith an example.

FIG. 9B illustrates a front view thereof.

FIG. 9C illustrates a left-side view thereof.

FIG. 9D illustrates a right-side view thereof.

FIG. 9E illustrates a top view thereof.

FIG. 9F illustrates a bottom view thereof.

FIG. 10A illustrates a perspective view of panel having illuminated pathsegments arranged to depict the asterism Little Dipper, in accordancewith an example.

FIG. 10B illustrates a front view thereof.

FIG. 10C illustrates a left-side view thereof.

FIG. 10D illustrates a right-side view thereof.

FIG. 10E illustrates atop view thereof.

FIG. 10F illustrates a bottom view thereof.

FIG. 11A illustrates a perspective view of panel having illuminated pathsegments arranged to depict the asterism Big Dipper, in accordance withan example.

FIG. 11B illustrates a front view thereof.

FIG. 11C illustrates a left-side view thereof.

FIG. 11D illustrates a right-side view thereof.

FIG. 11E illustrates a top view thereof.

FIG. 11F illustrates a bottom view thereof.

DETAILED DESCRIPTION

Various examples of systems, devices, and/or methods are describedherein. Words such as “example” and “exemplary” that may be used hereinare understood to mean “serving as an example, instance, orillustration.” Any implementation, and/or feature described herein asbeing an “example” or “exemplary” is not necessarily to be construed aspreferred or advantageous over any other embodiment, implementation,and/or feature unless stated as such. Thus, other embodiments,implementations, and/or features may be utilized, and other changes maybe made without departing from the scope of the subject matter presentedherein.

Accordingly, the examples described herein are not meant to be limiting.It will be readily understood that the aspects of the presentdisclosure, as generally described herein, and illustrated in thefigures, can be arranged, substituted, combined, separated, and designedin a wide variety of different configurations.

Further, unless the context suggests otherwise, the features illustratedin each of the figures may be used in combination with one another.Thus, the figures should be generally viewed as component aspects of oneor more overall embodiments, with the understanding that not allillustrated features are necessary for each embodiment.

Additionally, any enumeration of elements, blocks, or steps in thisspecification or the claims is for purposes of clarity. Thus, suchenumeration should not be interpreted to require or imply that theseelements, blocks, or steps adhere to a particular arrangement or arecarried out in a particular order.

Moreover, terms such as “substantially,” or “about” that may be usedherein, are meant that the recited characteristic, parameter, or valueneed not be achieved exactly, but that deviations or variations,including, for example, tolerances, measurement error, measurementaccuracy limitations and other factors known to those of ordinary skillin the art, may occur in amounts that do not preclude the effect thecharacteristic was intended to provide.

Introduction

As noted above, in an effort to improve customer experience, aircraftoperators may specify that the interior of the aircraft be decorated ina particularly pleasing manner and/or that the interior of the aircraftinclude certain amenities. The examples disclosed herein describe apanel for the interior of an aircraft that includes photoluminescentgraphics and a method for manufacturing the panels. While the examplesherein are described in connection with aircraft, the examples can beapplied to other types of vehicles such (e.g., cars, ships, trains).Additionally, the examples can be applied to non-vehicular structuressuch as signage, billboards, walls, etc. In some examples, the graphicscorrespond to asterisms and/or constellations. As used herein, the termasterism refers to a popularly known pattern or group of stars that canbe seen in the night sky. The term constellation refers to a group ofstars that forms an imaginary outline or pattern on the celestial spheresuch as an animal, mythological person or creature, a god, or aninanimate object. In some other examples, the graphics can correspond toany shape or figure that passengers may find pleasing.

A combination of photoluminescent path segments arranged on the paneland illuminating openings formed therein can be utilized to depict therespective frames and stars of the asterisms and constellations. Duringthe flight, the pilot or cabin attendant of the aircraft may dim theambient lighting in the cabin and activate the illumination devices sothat the asterisms and/or constellations become visible to thepassengers. For example, the cabin attendant may press a button at acabin attendant panel (CAP) of the aircraft, which may trigger anautomated process of setting the cabin ambient lighting to theparticular phase of flight at hand, for example, a sleep phase. A cabinservices system (CSS) in communication with the CAP may communicatesignals to the cabin lighting system of the aircraft to create aparticular dynamic scene. As the cabin lights dim, the CSS may controlthe illumination devices to brighten, and the asterisms and/orconstellations may subsequently become visible to the passengers.

The sudden appearance of the asterisms and/or constellations may givepassengers a sense of wonder and improve the passenger experience.Additionally, rendering the asterisms and/or constellations visibleduring certain periods of the flight can be utilized to indicate thestatus of the flight. For example, the asterisms and/or constellationscan be made visible when the aircraft is within one hour of landing.Passengers that frequently utilize the operator's aircraft may come toassociate the rendering of the asterisms and/or constellations with theaircraft being close to its final destination.

FIG. 1A illustrates an aircraft 100. FIG. 1B illustrates an interiorsection of the aircraft, in accordance with an example. The aircraft 100includes a plurality of panels 105 configured for attachment to aninterior of a fuselage of the aircraft 100. An example of the aircraft100 can correspond to a large commercial passenger jet. The panels 105can be arranged in a passenger section of the aircraft 100. The panels105 can be arranged on the ceiling and/or overhead compartments of thepassenger section of the aircraft 100. It should be noted that while thepanels 105 are described herein in connection with a commercialpassenger jet, examples of the panel can be adapted for use in othertypes of vehicles. For example, the panels can be utilized in buses,trains, and ships. The panels 105 can be used in other environments.

FIG. 2A illustrates a more detailed rendering of a panel 105 that cancorrespond to one or more panels of the cabin of the aircraft 100. FIG.2B illustrates a side view of a portion of the panel 105. Referring tothe figures, the panel 105 includes a substrate 205, a path segment 210,and an overlay material 215. The path segment 210 is arranged on asurface 206 of the substrate 205. The path segment 210 is formed from aphotoluminescent material. The overlay material 215 is arranged on thepath segment 210. The overlay material 215 is configured to render thepath segment 210 substantially invisible under an ambient photopiccondition (i.e., luminance levels of 10 to 10⁸ cd/m²) and render thepath segment 210 visible under an ambient mesopic (i.e., luminancelevels of 0.001 to 3 cd/m²) or scotopic condition (i.e., luminancelevels of 10⁻³ to 10⁻⁶ cd/m²). The luminance levels above can correspondto the luminance levels measured in proximity to passenger seating,which can be measured by an optical power and wavelength metermanufactured by, for example, GL Optic. A different example of theoverlay material 215 can be configured to render the path segment 210substantially invisible under luminance levels different from thoseassociated with the ambient photopic condition levels, and visible underluminance levels different from those associated with the ambientmesopic and/or scotopic conditions levels.

An example of the substrate 205 can correspond to a ridged material. Forexample, the substrate 205 can include a honeycomb core such as a Nomex®honeycomb core. The honeycomb core can be faced with, for example, oneor two skin plies of glass/phenolic prepreg. In some implementations,the substrate 205 can be formed via a “Crush core” process. Such aprocess facilitates forming substrates having curved shapes andconsistent thicknesses, which ensures a good fit and finish duringinstallation. In this regard, an example of the substrate 205 can beformed to have a thickness, T, of about 0.5-inch thick, with a 0.12-inchcell size. An example of the substrate 205 can be formed to havedimensions of about be about 4 ft by 8 ft. An example of the substrate205 can have a curved shaped configured to follow the contour of theinterior of the cabin of the aircraft 100. Other examples of thesubstrate 205 can be formed to have different thickness, dimensionsand/or shapes.

As illustrated in FIG. 2C, in some examples, the substrate 205 caninclude a decorative film layer 207, and the film layer 207 can bedisposed over the face material of the substrate 205. An example of thefilm layer 207 can include one or more layers of printed and/or texturedfilms and a protective layer. Another example of the film layer 207 cancorrespond to a polyvinyl fluoride (PVF) film such as Tedlar®. The filmlayer 207 can be fixed to the substrate 205 with an adhesive such as anepoxy adhesive, a phenolic adhesive, or a polyurethane adhesive.

As noted above, the path segment 210 is arranged on the surface 206 ofthe substrate 205. The path segment 210 is formed from aphotoluminescent material. One example of the photoluminescent materialcan correspond to a phosphorescent material. Phosphorescent materials donot immediately discharge all the radiation they absorb. Rather,phosphorescent materials discharge radiation at a lower intensity for upto several hours after initial excitation. In this regard, one exampleof the path segment 210 can, for example, discharge radiation at aluminosity level of at least 0.041 cd/m² for at least 1 hour. Thesedischarges can occur in different dominant emission wavelengths such asin the violet region (380-450 nm), the green blue region (490-560 nm),the blue region (450-450 nm), and the red region (635-700 nm) of theelectromagnetic spectrum. In some examples, the discharges can occur indifferent emission wavelengths regions.

One example of the photoluminescent material can correspond to a mixturethat includes strontium aluminate (SrAl₂O₄) and an adhesive such as awater based acrylic medium. One example of a water based acrylic mediumincludes a mixture of a gloss medium by Liquitex®, a varnish, and analkyd. One example of the alkyd is a polyester resin such as Liquin®manufactured by Winsor & Newton®. In this regard, the photoluminescentmaterial can discharge light in the 490-520 nm range. The wavelength canbe measured using an optical power and wavelength meter manufactured by,for example, GL Optic. In some examples of the photoluminescentmaterial, the chemistry can be altered so that the photoluminescentmaterial discharges light in the violet range (<490 nm). For example,the chemistry can be altered by utilizing different phosphorescentmaterials in different combinations such as strontium, magnesium,calcium, barium, silicon, or titanium. In some cases, alkaline earthmetals can be added with fluorescent pigments. Table 1 lists otherexample phosphor/dopant combinations from which the photoluminescentmaterial can be derived along with the color of light discharged by eachcombination.

TABLE 1 Phosphor:Dopant Perceived Color (Wavelength) SrAl2O4:Eu, Dygreen (510-525 nm) Sr4Al14O25:Eu, Dy blue green (407-494 nm)Sr2MgSi2O7:Eu, Dy blue green (456 nm) Y2O2S:Eu, Mg, Ti light red (620nm) CaAl2O4:Eu, Nd violet (440-450 nm) CaS:Eu, Tm light red (640 nm)ZnS:Cu, Mn, Co yellow orange (515-560 nm) ZnS:Cu, Ce yellow green(460-560 nm)

An example of the photoluminescent material can be configured to producea particular luminosity level. In this regard, the photoluminescentmaterial can correspond to a mixture that includes strontium aluminate,an adhesive, and a dopant. An example of the dopant can correspond toeuropium (Eu). The addition of the dopant facilitates trapping thephotons in an excited state.

In some cases, the particle size of the photoluminescent material isselected to produce a particular luminosity. For example, aphotoluminescent material having a large average particle size(e.g., >160 microns) can discharge light at a luminosity of about 0.25cd/m² for at least 20 minutes. The particle size can be determinedusing, for example, a particle size analyzer (PSA) which can beconfigured to determine the particle size of a substance via highdefinition image processing, analysis of Brownian motion, gravitationalsettling of the particle and/or light scattering (Rayleigh and Miescattering) of the particles. A photoluminescent material having smallaverage particle size (e.g., 25 microns) can discharge light at aluminosity of about 0.10 cd/m² for at least 20 minutes.

In some instances, the thickness, T2, of the photoluminescent materialcan be selected to produce a particular luminosity level. For example, anominal thickness, T2, of 300-400 microns can result in aphotoluminescent material having a luminosity of greater than 0.4 cd/m².A thicker layer of photoluminescent material can have a greaterluminosity. Thus, the thicker the photoluminescent material, the easierit can be for a passenger to see a pattern formed from thephotoluminescent material under a particular lighting condition in theaircraft cabin.

One issue with forming the path segment 210 from a material thatincludes SrAl₂O₄ is that the path segment 210 can tend to have a paleyellow color in daylight. In this case, any shape defined by the pathsegment 210 can be slightly visible to the naked eye under ambientdaylight conditions. The overlay material 215 discussed above can bearranged on the path segment 210 to mask and/or alleviate this issue.

The overlay material 215 is configured to facilitate the observation oflight discharged from the path segment 210 under darkened conditions andto mask the pale yellow color of the path segment 210 under daylightconditions. More specifically, the overlay material 215 is configured torender the path segment 210 substantially invisible under an ambientphotopic condition (i.e., luminance levels of 10 to 10⁸ cd/m²) and torender the path segment 210 visible under an ambient mesopic (i.e.,luminance levels of 0.001 to 3 cd/m²) or scotopic condition (i.e.,luminance levels of 10⁻³ to 10⁻⁶ cd/m²). In this regard, the overlaymaterial 215 is further configured to allow blue wavelengths to passthrough the overlay material 215 to facilitate charging thephotoluminescent material, and to facilitate the discharge of, forexample, blue or green emissions under ambient mesopic or scotopicconditions. One example of an overlay material 215 with thesecharacteristics is a bandpass filter film such as a Delta continuouslyvariable bandpass filter film.

As noted above, the overlay material 215 can be arranged on the pathsegment 210. In some cases, an adhesive can be utilized to fix theoverlay material 215 to the path segment 210. An example of the overlaymaterial 215 can have the same dimensions as the path segment 210. Forexample, the overlay material 215 can have the same length and width asa particular path segment 210 covered by the overlay material 215. Incases, where the sides of the path segment 210 can otherwise be exposedto ambient light, the overlay material 215 can be dimensioned to coverthe entire surface of the path segment 210 and the sides of the pathsegment 210 so that no portion of the path segment 210 is directlyexposed to ambient light.

An example of the panel 105 can include one or more openings 220 formedin the substrate 205. The path segment 210 can linearly extend between apair of openings 220. An example of the opening 220 can extend throughthe entire substrate 205. The opening 220 can have a circular shape, asquare shape, or a different shape. In the case of a circular shape, insome example, the opening 220 can have a diameter, D, of about 1 mm(e.g., when a fiber optic cable is arranged in the opening). In adifferent example, the opening 220 can have a diameter, D, of 3-4 mm(e.g., when an LED is arranged in the opening).

FIG. 3A illustrates an example of a panel 105 with an illuminationdevice 305 arranged in an opening 220 of the substrate 205 of the panel105. The illumination devices 305 can help accentuate the intersectionsbetween path segments 210, which in turn can allow a passenger to moreeasily identify a particular shape defined by the path segments 210. Theillumination device 305 is configured to emit light that then passesthrough the opening 220. Examples of illumination devices 305 includelight-emitting diodes (LEDs) and incandescent bulbs. While theillumination device 305 is illustrated as being within the opening 220,in other examples of the panel 105, the illumination device 305 can bearranged proximate to the opening 220. For example, the illuminationdevice 305 can be arranged below the substrate 205 or can protrudethrough the opening 220 to an extent.

The illumination device 305 can be electrically connected to acontroller (not shown) configured to generate a voltage to power theillumination device 305. An example of the controller can correspond tothe above-referenced cabin services system (CSS). The controller can beconfigured to adjust the brightness of the illumination device 305responsive to a command from the pilot of the aircraft 100.

FIG. 3B illustrates an example of a panel 105 that utilizes a group offiber optic cables 315 to optically distribute light emitted from anillumination device 305 to a group of openings 220 in the substrate 205.For example, twenty fiber optic cables 315 can distribute light emittedfrom a single illumination device 305 to twenty different openings 220.A different numbers of fiber optic cables 315 can distribute lightemitted from one or more illumination devices 305 to a different numberof openings 220. The illumination device 305 can be arranged on or belowa side of the substrate 205 opposite the path segment 210. First ends312 of the fiber optic cables 315 can be arranged in proximity to theillumination device 305 and second ends 313 of the fiber optic cables315 can be arranged within or proximate to different openings 220 formedin the substrate 205. In some examples of the panel, the illuminationdevice 305 and the fiber optic cables 315 can be fixed to the bottomsurface of the substrate 205 with, for example, an adhesive.

FIG. 3C illustrates an example of a panel 105 that utilizes a light pipe310 to optically distribute light emitted from an illumination device305 to a group of openings 220 in the substrate 205. For example, thelight pipe 310 can define twenty different pathways. The pathways candistribute light emitted from a single illumination device 305 to twentydifferent openings 220. The illumination device 305 can be arranged onor below a side of the substrate 205 opposite the path segment 210. Thelight pipe 310 can have a first end 317 arranged in proximity to theillumination device 305 and one or more pipe terminals 320 arrangedwithin or proximate to different openings 220 formed in the substrate205. In some examples of the panel, the illumination device 305 and thelight pipe 310 can be fixed to the bottom surface of the substrate 205with, for example, an adhesive.

In an example of the panel 105, rather than forming openings in thesubstrate 205, a circuit (not shown) that includes one or moreillumination devices 305 (e.g., LEDs) can be printed on the top of thesubstrate 205. Printing the circuit can be more cost effective thanforming the openings. The illumination devices 305 can be arranged atlocations corresponding to endpoints of the path segments 210. Thecircuit can then be overlaid by the film layer 207 (e.g., Tedlar®), andlight emitted from the illumination devices 305 can be seen through thefilm layer 207. As noted above, illumination devices 305 can helpaccentuate the intersections between path segments 210, which in turncan allow a passenger to more easily identify a particular shape definedby the path segments 210.

Referring back to FIG. 2A, an example of the panel 105 can have a groupof path segments 210 and openings 220 arranged in a recognizable shape.For example, the shape can correspond to an asterism (250 and 255)(i.e., a popularly known pattern or group of stars that can be seen inthe night sky). Under darkened conditions, the openings 220 can beilluminated by the illumination device 305 to represent the stars of theasterism, and light emitted from photoluminescent material of the pathsegments 210, arranged between the openings, can be visible. Thecombined illuminated openings 220 and visible path segments 210 depictthe asterism (250 and 255). Within examples, the asterism 250 representsThe Big Dipper and the asterism 255 represents The Little Dipper asillustrated in FIG. 2A. Other asterisms can be represented by variouscombinations of illuminated openings 220 and path segments 210. Anon-exhaustive list of internationally recognized asterisms that can berepresented by particular arrangements of openings 220 and path segments210 includes the Summer Triangle, the Great Square of Pegasus, theSickle of Leo, the Diamond Ring, the Coathanger.

FIG. 4 illustrates an example of a panel 400 depicting the shape of aconstellation 405. The constellation 405 corresponds to Ursa Major, asseen by the naked eye. Under darkened conditions, the openings 220 canbe illuminated by the illumination device 305 to represent the stars ofthe constellation 405 and the light emitted from the photoluminescentmaterial of the path segments 210 arranged between the openings can bevisible. The combined illuminated openings 220 and visible path segments210 depict the constellation 405. Anon-exhaustive list ofinternationally recognized constellations 405 that can be represented byparticular arrangements of openings 220 and path segments 210 includesAquarius, Aquila, Aries, Canis Major, Cassiopeia, Cygnus, Gemini, Leo,Lyra, Ursa minor, Wheat of Virgo, and Orion.

In some cases, less well known but regionally significant constellationscan be represented by particular arrangements of openings 220 and pathsegments 210. For example, a non-exhaustive list of constellations 405known to inhabitants of the islands of the Pacific that can berepresented by particular arrangements of openings 220 and path segments210 includes Ke Ka o Makali'i (“The Canoe-Bailer of Makali'i”),Iwikuamo'o (“Backbone”), Manaiakalani (“The Chief s Fishline”), and KaLupe o Kawelo (“The Kite of Kawelo”). Other constellations 405 known toinhabitants of other regions of the world can be represented. Forexample, constellations known to the inhabitants of Asia, Europe, andAfrica can be represented.

In yet other examples, the substrate can include a plethora of openings220 and the illumination devices 305 utilized to illuminate the openings220 can be dynamically activated to show various combinations ofpatterns via the openings 220. A computer can control the illuminationdevices 305 to activate according to, for example, a location of theaircraft, and predefined patterns.

As noted above, illuminated openings 220 and photoluminescent pathsegments 210 can be arranged in a myriad of patterns or any other imageor shape to depict any shape or pattern. For example, the shape cancorrespond to a cartoon character. The shape can correspond to a companylogo. The shape can correspond to a word or phrase. The shape cancorrespond to other images or shapes.

FIG. 5 illustrates an example of a method for manufacturing the panel105 of FIG. 1B. Block 500 involves forming a path segment 210 on asurface 206 of a substrate 205 from a photoluminescent material, asillustrated in FIG. 6A.

The substrate 205 can correspond to a conformed rigid material such as aNomex® honeycomb core. The honeycomb core can be faced with, forexample, one or two skin plies of glass/phenolic prepreg. The substrate205 can have a thickness, T, of about 0.5-inch thick, with a 0.12-inchcell size, and can have a surface area of about be about 4 ft by 8 ft.One or more layers of printed, textured, and/or protective film layerssuch as printed, textured, and/or protective film layers formed from amaterial such as Tedlar® can be attached to the substrate 205 with, forexample, an adhesive.

An example of the photoluminescent material corresponds to a mixturethat comprises strontium aluminate and an adhesive. A different exampleof the photoluminescent material can correspond to a mixture thatcomprises strontium aluminate, an adhesive, and a dopant. Thephotoluminescent material can, for example, discharge radiation at aluminosity level of at least 0.2 cd/m² for at least 30 minutes. Thethickness, T2 of the photoluminescent material can be selected toproduce a desired luminosity level. For example, a thickness, T2, of300-400 microns can result in a photoluminescent material having aluminosity of greater than 0.4 cd/m². A thicker layer ofphotoluminescent material can have a greater luminosity.

An example of forming the path segment 210 involves a masking process.For example, a mask can be arranged on the surface 206 of the substrate205. The mask can define one or more cut-outs having particular shapesat locations associated with particular path segments 210. For example,the shape of the cut-out (i.e., length and width) can match the lengthand width of a particular path segment 210. An example of the mask canhave a thickness that matches the desired thickness of the path segment210. For example, the thickness of the mask can correspond to thedesired thickness, T2, of the path segment 210.

After arranging the mask on the surface 206 of the substrate 205, thephotoluminescent material can be applied over the mask. In this regard,the photoluminescent can be in an uncured state. For example, thephotoluminescent material can be in a liquid or gel state. Thephotoluminescent material can be spread evenly over the mask by a wipingoperation.

After applying the photoluminescent material, the mask can be removed,and the photoluminescent material can be allowed to cure. Some examplesof the photoluminescent material can cure in the presence of air or viaa chemical reaction. The curing time of an example of thephotoluminescent material can be reduced by heating the photoluminescentmaterial. In some instances, the operations above can be repeated tobuild up successive layers of photoluminescent material to facilitateincreasing the thickness of the photoluminescent material.

Another example for forming the path segment 210 involves depositing thephotoluminescent material onto the surface 206 of the substrate 205. Forexample, the photoluminescent material can be provided in a liquidstate. The liquid photoluminescent material can be sprayed/printed ontothe substrate 205 via a nozzle. The nozzle can be movable relative tothe substrate 205 according to two degrees of freedom. In this regard, acomputer can control the relative movement of the nozzle and the openingand closing of the nozzle to deposit the photoluminescent material. Forexample, the substrate 205 can be arranged on an X-Y table. The computercan control the X-Y table to move the substrate 205 under the nozzle andcan control the nozzle to open and close in particular regions to formthe path segments 210 on the substrate 205.

Another example for forming the path segment 210 involves utilizing aprinting process, such as a silkscreen printing process, for example, toapply the photoluminescent material to the substrate 205. In silkscreenprinting, an emulsion is spread over a screen and selectively cured witha negative of the desired pattern of the path segment 210. The uncuredparts of the emulsion are washed off the screen leaving openings in themesh of the screen in locations corresponding to the path segment 210.The photoluminescent material can then be spread on to the screen tofill the openings in the mesh of the screen associated with the pathsegment 210. The screen can then be pressed onto the substrate 205.Capillary pressure draws the photoluminescent material from the openingsof the mesh to the surface 206 of the substrate 205. The screen can thenbe removed, leaving behind photoluminescent material having a pattern ofthe path segment 210. The photoluminescent material can then be cured(e.g., air dried, chemically cured, UV cured, etc.).

In some instances, the operations above can be repeated to build upsuccessive layers of photoluminescent material to facilitate increasingthe thickness of the photoluminescent material.

In the case of a panel 105 having a film layer 207 on the substrate 205(See FIG. 2C), an example for forming the path segment 210 can involveutilizing any of the above techniques to form the path segment 210 onthe film layer 207 of the substrate 205 before applying the film layer207 to the substrate 205. One example of this method involves providingthe film layer 207 as a roll of film and utilizing a printer to depositthe photoluminescent material on to the roll of film. Afterward, thephotoluminescent material can be cured as described above. The film rollcan then be cut to a desired size and shape and applied to the substrate205, as described above.

Block 505 involves overlaying the path segment 210 with an overlaymaterial 215, as illustrated in FIG. 6B. As noted above, one issue withforming the path segment 210 from a photoluminescent material such asSrAl₂O₄ is that the path segment 210 can tend to have a pale yellowcolor under an ambient photopic condition (i.e., luminance levels of 10to 10⁸ cd/m²). The overlay material 215 is configured to render the pathsegment 210 substantially invisible under an ambient photopic conditionand render the path segment 210 visible under an ambient mesopic orscotopic condition (i.e., luminance levels of 10⁻³ to 10⁻⁶ cd/m²).

One example of the overlay material 215 can correspond to the lightenhancement film described above. In this case, the overlay material 215can be configured to allow sufficient blue wavelengths to pass throughthe overlay material 215 to facilitate charging the photoluminescentmaterial, and to facilitate viewing the discharge of blue or greenemission from the photoluminescent material under in the mesopic orscotopic condition conditions.

The overlay material 215 can be cut into the shape of the path segment210 so that the overlay material 215 has the same general dimensions asthe path segment 210. To prevent exposure of the edges of the pathsegment 210 to ambient light, the overlay material 215 can bedimensioned to cover the entire exposed surface of the path segment 210so that no portion of the path segment 210 is directly exposed toambient light.

After cutting the overlay material 215 into the desired shape, theshaped overlay material 215 can be fixed to the top of the path segment210. For example, the shaped overlay material 215 can be adhered to thetop of the path segment 210 with an adhesive such as the water basedacrylic medium described above.

Another example of the overlay material 215 can correspond to a thinlayer of a translucent material having a color that matches thebackground of the panel 105. For example, in the case of a panel 105having a white background, the overlay material 215 can correspond to awhite translucent material or a different color that, when combined withthe pale yellow color of the photoluminescent material, renders the pathsegment 210 invisible to the naked eye under daylight conditions. Theoverlay material 215 can have a thickness smaller than 500 μm, smallerthan 250 μm, and even smaller than 100 μm. The overlay material 215 canbe applied to the path segment 210 by utilizing any of the depositingtechniques described above. For example, the overlay material 215 can beapplied over the path segment 210 via a masking process, depositionprocess, or a silkscreen process.

Block 510 involves forming openings 220 in the substrate 205, asillustrated in FIG. 6C. Some examples for forming the openings 220 inthe substrate 205 can involve drilling the openings 220 into the panel105 with a drill bit or laser or forming the substrate 205 in a moldthat defines the openings 220 in the substrate 205. The openings 220 canextend through the entire substrate 205. The openings 220 can have acircular shape, a square shape, or a different shape. In the case of acircular shape, in some example, the opening 220 can have a diameter, D,of about 1 mm (e.g., when a fiber optic cable is arranged in theopening). In a different example, the opening 220 can have a diameter,D, of 3-4 mm (e.g., when an LED is arranged in the opening).

Block 515 involves arranging an illumination device 305 within theopenings 220 formed in the substrate 205, as illustrated FIGS. 3A-3C. Asnoted above, the illumination device 305 can correspond to alight-emitting diode (LED) or an incandescent bulb. The illuminationdevice 305 can be arranged within the opening 220 or proximate to theopening (e.g., just below the opening 220, or protruding from theopening 220). The illumination device 305 can be arranged on or below aside of the substrate 205 opposite the path segment 210, and a lightpipe 310 or fiber optic cable 315 can be utilized to opticallydistribute light emitted from the illumination device 305 to groups ofopenings 220.

FIG. 7 illustrates another example of a method for manufacturing a panel105. Block 700 involves forming a path segment 210 on a surface 206 of asubstrate 205 from a photoluminescent material.

Block 705 involves overlaying the path segment 210 with an overlaymaterial 215, wherein the overlay material 215 is configured to renderthe path segment 210 substantially invisible under an ambient photopiccondition and render the path segment 210 visible under an ambientmesopic or scotopic condition.

Some examples of the method can involve forming two or more openings 220in the substrate 205, wherein the path segment 210 linearly extendsbetween a pair of the two or more openings 220 of the plurality ofopenings 220; and arranging one or more illumination devices 305 inproximity to the two or more openings 220 to illuminate endpoints of thepath segment 210.

In some examples, arranging one or more illumination devices 305 caninvolve arranging a fiber optic cable 315 in proximity to the two ormore openings 220.

In some examples, arranging one or more illumination devices 305 caninvolve arranging a light-emitting diode (LED) in proximity to the twoor more openings 220.

Some examples of the method can involve arranging the two or moreopenings 220 in a shape of an asterism (250 and 255) or constellation405; and forming a plurality of path segments 210 between differentpairs of openings 220 to thereby define a frame of the asterism (250 and255) or constellation 405.

In some examples of the method, forming the path segment 210 involvesforming the path segment 210 on the surface 206 of the substrate 205from a mixture that comprises strontium aluminate and an adhesive.

In some examples of the method, forming the path segment 210 involvesforming the path segment 210 on the surface 206 of the substrate 205from a mixture that comprises strontium aluminate, an adhesive, and adopant.

In some examples of the method, overlaying the path segment 210 involvesfacilitating the charging of the photoluminescent material under theambient photopic condition.

In some examples of the method, forming the path segment 210 on thesurface 206 of the substrate 205 involves forming the path segment 210on a face of a substrate 205 that includes a honeycomb core.

In some examples of the method, forming the path segment 210 on thesurface 206 of the substrate 205 involves forming the path segment 210on a surface of a polyvinyl fluoride (PVF) film.

In some examples of the method, forming the path segment 210 on thesurface 206 of the substrate 205 involves depositing thephotoluminescent material on the surface 206 of the substrate 205

FIG. 8 illustrates a method for illuminating an interior of a cabin ofan aircraft 100. Block 800 involves charging a photoluminescent materialin a path segment 210 arranged on a surface of a panel 105 of the cabinduring a first phase of a flight where an ambient light of the interiorof the cabin corresponds to a photopic condition.

Block 805 involves changing the ambient light of the interior of thecabin to a mesopic or scotopic condition during a second phase of theflight, wherein during the second phase of the flight, emissions fromthe photoluminescent material of the path segment 210 are visible.

An example of the method can involve maintaining the ambient light ofthe interior of the cabin at the photopic condition so that the pathsegment 210 is rendered substantially invisible during the first phaseof the flight.

An example of the method can involve rendering a frame of an asterism(250 and 255) or constellation 405 on the panel 105 visible during thesecond phase of the flight, wherein the frame of the asterism (250 and255) is defined by a plurality of path segments 210 that include thephotoluminescent material, and that extend between different pairs of aplurality of openings 220 on the panel 105.

In some examples of the method, rendering the frame of the asterism (250and 255) or the constellation 405 can involve illuminating anillumination device 305 arranged proximate to the plurality of openings220.

FIGS. 9A-11F illustrate various views of example panels havingilluminated path segments 210 arranged to depict various shapes. Theshape depicted on the example panel of FIGS. 9A-9F corresponds to theconstellation Ursa Major. The shape depicted on the example panel ofFIGS. 10A-10F corresponds to the asterism Little Dipper. The shapedepicted on the example panel of FIGS. 11A-11F corresponds to the BigDipper.

The path segments can be arranged on the panels differently. Forexample, the various shapes can be scaled, rotated, and/or offset tocover different areas of the respective panels. The shapes can berepeated on the respective panels. A combination of the shapes depictedon the various panels can be depicted on the same panel.

Moreover, the path segments can be arranged to show an entirelydifferent shape. For example, path segments can be arranged to depict acombination of one or more of the internationally recognizedconstellations Aquarius, Aquila, Aries, Canis Major, Cassiopeia, Cygnus,Gemini, Leo, Lyra, Ursa minor, Wheat of Virgo, and Orion. Otherinternationally recognized constellations can be depicted. The pathsegments can be arranged to depict a combination of one or more of theregionally recognized constellations Ke Ka o Makali'i (“The Canoe-Bailerof Makali'i”), Iwikuamo'o (“Backbone”), Manaiakalani (“The Chief sFishline”), and Ka Lupe o Kawelo (“The Kite of Kawelo”). Otherconstellations regionally recognized in different parts of the world canbe depicted.

Further, the disclosure comprises embodiments according to the followingclauses:

Clause 1. A method for manufacturing a panel, the method comprising:forming a path segment on a surface of a substrate from aphotoluminescent material; and overlaying the path segment with anoverlay material, wherein the overlay material is configured to renderthe path segment substantially invisible under an ambient photopiccondition and render the path segment visible under an ambient mesopicor scotopic condition.

Clause 2. The method according to clause 1, further comprising: formingtwo or more openings in the substrate, wherein the path segment linearlyextends between a pair of the two or more openings; and arranging one ormore illumination devices in proximity to the two or more openings toilluminate endpoints of the path segment.

Clause 3. The method according to any of the proceeding clauses, whereinarranging one or more illumination devices comprises arranging a fiberoptic cable in proximity to the two or more openings.

Clause 4. The method according to any of the proceeding clauses, whereinarranging one or more illumination devices comprises arranging alight-emitting diode (LED) in proximity to the two or more openings.

Clause 5. The method according to any of the proceeding clauses, furthercomprising: arranging the two or more openings in a shape of an asterismor constellation; and forming a plurality of path segments betweendifferent pairs of openings to thereby define a frame of the asterism orconstellation.

Clause 6. The method according to any of the proceeding clauses, whereinforming the path segment comprises forming the path segment on thesurface of the substrate from a mixture that comprises strontiumaluminate and an adhesive.

Clause 7. The method according to any of the proceeding clauses, whereinforming the path segment comprises forming the path segment on thesurface of the substrate from a mixture that comprises strontiumaluminate, an adhesive, and a dopant.

Clause 8. The method according to any of the proceeding clauses, whereinoverlaying the path segment comprises facilitating charging of thephotoluminescent material under the ambient photopic condition.

Clause 9. The method according to any of the proceeding clauses, whereinforming the path segment on the surface of the substrate comprisesforming the path segment on a face of a substrate that includes ahoneycomb core.

Clause 10. The method according to any of the proceeding clauses,wherein forming the path segment on the surface of the substratecomprises forming the path segment on a surface of a polyvinyl fluoride(PVF) film.

Clause 11. The method according to any of the proceeding clauses,wherein forming the path segment comprises: depositing thephotoluminescent material on the surface of the substrate.

Clause 12. A panel for an interior cabin of an aircraft, the panelcomprising: a substrate; a path segment arranged on a surface of thesubstrate, the path segment formed from a photoluminescent material; andan overlay material arranged on the path segment, wherein the overlaymaterial is configured to render the path segment substantiallyinvisible under an ambient photopic condition and render the pathsegment visible under an ambient mesopic or scotopic condition.

Clause 13. The panel according to clause 12, further comprising: two ormore openings formed in the substrate, wherein the path segmentcorresponds to a linearly that extends between a pair of the two or moreopenings; and one or more illumination devices arranged in proximity tothe two or more openings to illuminate endpoints of the path segment.

Clause 14. The panel according to any of the preceding clauses startingfrom clause 12, wherein at least some of the one or more illuminationdevices correspond to a fiber optic cable.

Clause 15. The panel according to any of the preceding clauses startingfrom clause 12, wherein at least some of the one or more illuminationdevices correspond to a light-emitting diode (LED).

Clause 16. The panel according to any of the preceding clauses startingfrom clause 12, wherein the two or more openings are arranged to definea shape of an asterism or a constellation, wherein the panel furthercomprises a plurality of path segments, formed from the photoluminescentmaterial, between different pairs of openings to thereby form a frame ofthe asterism or the constellation.

Clause 17. The panel according to any of the preceding clauses startingfrom clause 12, wherein the photoluminescent material comprises amixture of strontium aluminate and an adhesive.

Clause 18. A vehicle that corresponds to an aircraft comprising: aplurality of panels configured for attachment to an interior of afuselage, wherein at least one panel of the plurality of panelscomprises: a substrate having a surface; a path segment arranged on thesurface of the substrate, the path segment formed from aphotoluminescent material; and an overlay material arranged on the pathsegment, wherein the overlay material is configured to render the pathsegment substantially invisible under an ambient photopic condition andrender the path segment visible under an ambient mesopic or scotopiccondition.

Clause 19. A vehicle that corresponds to a bus comprising: a pluralityof panels configured for attachment to an interior of the bus, whereinat least one panel of the plurality of panels comprises: a substratehaving a surface; a path segment arranged on the surface of thesubstrate, the path segment formed from a photoluminescent material; andan overlay material arranged on the path segment, wherein the overlaymaterial is configured to render the path segment substantiallyinvisible under an ambient photopic condition and render the pathsegment visible under an ambient mesopic or scotopic condition.

Clause 20. A vehicle that corresponds to a train comprising: a pluralityof panels configured for attachment to an interior of the train, whereinat least one panel of the plurality of panels comprises: a substratehaving a surface; a path segment arranged on the surface of thesubstrate, the path segment formed from a photoluminescent material; andan overlay material arranged on the path segment, wherein the overlaymaterial is configured to render the path segment substantiallyinvisible under an ambient photopic condition and render the pathsegment visible under an ambient mesopic or scotopic condition.

Clause 21. A vehicle that corresponds to an automobile comprising: aplurality of panels configured for attachment to an interior of theautomobile, wherein at least one panel of the plurality of panelscomprises: a substrate having a surface; a path segment arranged on thesurface of the substrate, the path segment formed from aphotoluminescent material; and an overlay material arranged on the pathsegment, wherein the overlay material is configured to render the pathsegment substantially invisible under an ambient photopic condition andrender the path segment visible under an ambient mesopic or scotopiccondition.

Clause 24. The vehicle according to the any of preceding clauses fromclause 18, further comprising: two or more openings formed in thesubstrate, wherein the path segment corresponds to a linearly thatextends between a pair of the two or more openings; and one or moreillumination devices arranged in proximity to the two or more openingsto illuminate endpoints of the path segment.

Clause 25. The vehicle according to the any of preceding clauses fromclause 18, wherein at least some of the one or more illumination devicescorrespond to a fiber optic cable.

Clause 26. The vehicle according to the any of preceding clauses fromclause 18, wherein at least some of the one or more illumination devicescorrespond to a light-emitting diode (LED).

Clause 27. The vehicle according to the any of preceding clauses fromclause 18, wherein the two or more openings are arranged to define ashape of an asterism or a constellation, wherein the panel furthercomprises a plurality of path segments, formed from the photoluminescentmaterial, between different pairs of openings to thereby form a frame ofthe asterism or the constellation.

Clause 28. The vehicle according to the any of preceding clauses fromclause 18, wherein the photoluminescent material comprises a mixture ofstrontium aluminate and an adhesive.

While the systems and methods of operation have been described withreference to certain examples, it will be understood by those skilled inthe art that various changes can be made and equivalents can besubstituted without departing from the scope of the claims. Therefore,it is intended that the present methods and systems not be limited tothe particular example disclosed, but that the disclosed methods andsystems include all embodiments falling within the scope of the appendedclaims.

What is claimed is:
 1. A method for manufacturing a panel, the methodcomprising: forming a path segment on a surface of a substrate having aparticular color from a photoluminescent material having a particularcolor under an ambient photopic condition that is different from thecolor of the substrate; and overlaying the path segment with an overlaymaterial, wherein the overlay material has a color that when combinedwith the color of the photoluminescent material is configured to matchthe color of the substrate so that the path segment becomessubstantially invisible under an ambient photopic condition and whereinthe overlay material is configured to render the path segment visibleunder an ambient mesopic or scotopic condition.
 2. The method accordingto claim 1, further comprising: forming two or more openings in thesubstrate, wherein the path segment linearly extends between a pair ofthe two or more openings; and arranging one or more illumination devicesin proximity to the two or more openings to illuminate endpoints of thepath segment.
 3. The method according to claim 2, wherein arranging oneor more illumination devices comprises arranging a fiber optic cable inproximity to the two or more openings.
 4. The method according to claim2, wherein arranging one or more illumination devices comprisesarranging a light-emitting diode (LED) in proximity to the two or moreopenings.
 5. The method according to claim 2, further comprising:arranging the two or more openings in a shape of an asterism orconstellation; and forming a plurality of path segments betweendifferent pairs of openings to thereby define a frame of the asterism orconstellation.
 6. The method according to claim 1, wherein forming thepath segment comprises forming the path segment on the surface of thesubstrate from a mixture that comprises strontium aluminate and anadhesive.
 7. The method according to claim 1, wherein forming the pathsegment comprises forming the path segment on the surface of thesubstrate from a mixture that comprises strontium aluminate, anadhesive, and a dopant.
 8. The method according to claim 1, whereinoverlaying the path segment comprises facilitating charging of thephotoluminescent material under the ambient photopic condition.
 9. Themethod according to claim 1, wherein forming the path segment on thesurface of the substrate comprises forming the path segment on a face ofa substrate that includes a honeycomb core.
 10. The method according toclaim 1, wherein forming the path segment on the surface of thesubstrate comprises forming the path segment on a surface of a polyvinylfluoride (PVF) film.
 11. The method according to claim 1, whereinforming the path segment comprises: depositing the photoluminescentmaterial on the surface of the substrate.
 12. A panel for an interiorcabin of an aircraft, the panel comprising: a substrate having aparticular color; a path segment arranged on a surface of the substrate,the path segment formed from a photoluminescent material having aparticular color under an ambient photopic condition that is differentfrom the color of the substrate; and an overlay material arranged on thepath segment, wherein the overlay material has a color that whencombined with the color of the photoluminescent material is configuredto match the color of the substrate so that the path segment becomessubstantially invisible under an ambient photopic condition and whereinthe overlay material is configured to render the path segment visibleunder an ambient mesopic or scotopic condition.
 13. The panel accordingto claim 12, further comprising: two or more openings formed in thesubstrate, wherein the path segment corresponds to a linearly thatextends between a pair of the two or more openings; and one or moreillumination devices arranged in proximity to the two or more openingsto illuminate endpoints of the path segment.
 14. The panel according toclaim 13, wherein at least some of the one or more illumination devicescorrespond to a fiber optic cable.
 15. The panel according to claim 13,wherein at least some of the one or more illumination devices correspondto a light-emitting diode (LED).
 16. The panel according to claim 13,wherein the two or more openings are arranged to define a shape of anasterism or a constellation, wherein the panel further comprises aplurality of path segments, formed from the photoluminescent material,between different pairs of openings to thereby form a frame of theasterism or the constellation.
 17. The panel according to claim 12,wherein the photoluminescent material comprises a mixture of strontiumaluminate and an adhesive.
 18. An aircraft comprising: a plurality ofpanels configured for attachment to an interior of a fuselage, whereinat least one panel of the plurality of panels comprises: a substratehaving a surface having a particular color; a path segment arranged onthe surface of the substrate, the path segment formed from aphotoluminescent material having a particular color under an ambientphotopic condition that is different from the color of the substrate;and an overlay material arranged on the path segment, wherein theoverlay material has a color that when combined with the color of thephotoluminescent material is configured to match the color of thesubstrate so that the path segment becomes substantially invisible underan ambient photopic condition and wherein the overlay material isconfigured to render the path segment visible under an ambient mesopicor scotopic condition.
 19. The aircraft according to claim 18, whereinthe at least one panel further comprises: a plurality of openingsarranged to define a shape of an asterism or constellation; and aplurality of path segments, wherein the plurality of path segmentsextend between different pairs of the plurality of openings to therebyform a frame of the asterism or the constellation.
 20. The aircraftaccording to claim 19, wherein the at least one panel further comprises:an illumination device arranged in proximity to the plurality ofopenings to illuminate endpoints of the plurality of path segments.